JP7481711B2 - Status notification method in USB Type-C interface circuit, device having USB Type-C interface circuit, and information processing system - Google Patents

Description

The present invention relates to a USB (Universal Serial Bus) Type-C interface circuit, and in particular to a state notification method in a USB Type-C interface circuit.

The USB Type-C interface circuit is an interface circuit that connects both the host device and the device. Although the USB Type-C interface circuit is smaller than the interface circuits of previous USB devices, the number of poles has been significantly increased. Here, the interface circuits of previous USB devices refer to the USB Type-A interface circuit and the USB Type-B interface circuit. In addition, the USB Type-C interface circuit also supports insertion and removal (hot plugging) while the power is on, just as in the past. For this reason, the USB Type-C interface circuit is an interface circuit that is prone to abnormalities due to poor contact, etc.

In addition, in the case of a USB Type-C interface circuit, the user can identify the cause of an abnormality, such as a malfunction or failure to be recognized, by performing the following procedures. Here, the cause of the abnormality can be, for example, the USB device or the USB cable. In other words, the cause of the abnormality can only be identified by performing isolation procedures such as actually plugging and unplugging the USB Type-C interface circuit or replacing the USB device or USB cable.

In addition, various prior art documents related to the present invention are known.

For example, Patent Document 1 discloses an "electronic device" that can more reliably determine the interface type of a connected external device. Patent Document 1 discloses a technical idea that can determine whether a connected device is a Type-C device or a non-Type-C device. Note that a Type-C device refers to a device that has an interface that complies with the USB Type-C standard, and a non-Type-C device refers to a device that does not have an interface that complies with the USB Type-C standard.

Patent Document 2 discloses an "electronic device and its control method" that can determine the type of external device without using a storage unit such as a battery or capacitor, even if power to the external device is no longer supplied from a power supply terminal such as VBUS. Like Patent Document 1, Patent Document 2 also discloses a technical idea that can determine whether a connected device is a Type-C device or a non-Type-C device.

Patent Document 3 also discloses a "semiconductor device, a control method for the semiconductor device, and a power supply system" that can improve safety when supplying power to a USB device. In Patent Document 3, the power supply system has a host, a USB device, and a USB cable. The USB device can perform data communication with the host via the USB cable and can receive power from the host. As an example of the USB cable, a USB Type-C cable can be used. The host includes a power supply unit, a controller that controls the power supply unit, a resistor, and a switch. The controller includes a power supply control circuit, an abnormality detection circuit, and an abnormality state notification circuit. The power supply control circuit controls the power supply unit and the switch. The abnormality detection circuit determines whether the state of the voltage supply path is normal or abnormal. The abnormality detection circuit outputs the determination result to the abnormality state notification circuit. The abnormality state notification circuit notifies the fact that an abnormal state exists based on the determination result of the abnormality detection circuit. Specifically, the abnormality state notification circuit notifies the outside of the abnormality state with an alarm sound or an LED. The communication circuit may be used to notify the outside. In this way, in Patent Document 3, detection of abnormal conditions on the power line (VBUS) is performed within the Type-C controller.

Patent document 4 discloses a "short circuit determination method and electronic device" that can determine with high accuracy whether a short circuit has occurred between terminals due to the intrusion of foreign matter into a connector. In Patent document 4, the electronic device has a Type-C connector, a charging circuit, a switch, a resistor, a connection detection circuit, a monitoring circuit, a determination circuit, and a CC terminal control circuit. The monitoring circuit monitors voltage changes for each of the RX+ terminal and the RX2- terminal when a charging device is connected to the Type-C connector. The determination circuit uses the voltage changes monitored by the monitoring circuit to determine whether a short circuit has occurred between the UBUS terminal and the RX+ terminal and the RX- terminal. Then, when the rising timing of the RX+ voltage and the RX- voltage coincides with the rising timing of the UBUS voltage, the determination circuit determines that a short circuit has occurred due to the intrusion of foreign matter into the Type-C connector.

Patent Document 5 discloses an "electronic device" that can prevent burnout accidents when using an AC adapter that complies with the USB Type-C standard, even if the AC adapter does not have a burnout prevention function. In Patent Document 5, the electronic device includes a receptacle that complies with the USB Type-C standard, a system circuit, a rechargeable battery, a pull-down resistor, an FFT (Field effect transistor) switch, a control circuit, and a sense resistor. The receptacle includes a lock plate, a shell, a V _BUS pin, and a CC (Configuration Channel) pin. The receptacle is connected to a counterpart connector that complies with the USB Type-C standard. The counterpart connector is connected to a charging adapter that complies with the USB Type-C standard via a cable. The sense resistor is provided in a short-circuit current generating circuit between the shell and ground of the receptacle. If a current (a value equal to or greater than a significant value) is detected in the sense resistor, it means that a short-circuit current is generated between the shell and ground. The control circuit controls the FET switch to be disconnected when the current detected in the sense resistor satisfies a predetermined condition (for example, when the detected current exceeds a predetermined threshold value). When the FET switch is disconnected, the signal path corresponding to the CC pin that confirms the connection between the electronic device and the charging adapter is interrupted, so the charging adapter recognizes that the connection with the electronic device has been released and stops supplying power (the power supply of the charging adapter is controlled to be OFF).

Patent Document 6 discloses a power supply system and a power receiving device that can safely detect a short circuit in a power receiving device. In Patent Document 6, the power supply system is compliant with the USB Type-C standard and includes a power supply device and a power receiving device that are connected via a USB cable. The power supply device includes a power supply controller, and the power receiving device includes a power receiving controller. The power supply controller and the power receiving controller are each a port controller related to USB Type-C, and are connected to each other via a CC (Configuration Channel) line to provide a communication function. The power receiving device includes a short circuit detection circuit. When the bus switch is in an off state, the short circuit detection circuit detects a short circuit in a second bus line that is closer to the load circuit than the bus switch. When a short circuit is detected, the power receiving controller may notify the power supply controller of the short circuit on the load side by using communication on the CC line. In response to this notification, the power supply controller can stop the power supply circuit.

JP 2018-013932 A JP 2018-013933 A JP 2017-187933 A JP 2018-029451 A JP 2017-201862 A JP 2018-011442 A

Universal Serial Bus Type-C Cable and Connector Specification Revision 1.1, April 3, 2015 Universal Serial Bus Power Delivery Specification Revision 2.0, V1.1, 7 May 2015

The USB Type-C interface circuit has the following problems:

The first problem is that the USB Type-C interface circuit is prone to malfunctions due to poor contact, etc.

The reasons are as follows. While the interface circuit is becoming smaller, the number of signal lines (including power and ground) is greater than that of non-USB Type-C USB interface circuits (USB 2.0 Type-A: 4 lines, USB 3.0 Type-A: 9 lines, USB Type-C: 20 lines). In addition, the USB Type-C interface circuit can handle not only USB but also high-speed signals such as PCI-Express, DisplayPort, and HDMI (registered trademark) (High-Definition Multimedia Interface) by using it in alternate mode. The USB Type-C interface circuit can support not only the 5V used in non-USB Type-C USB interface circuits, but also up to 20V and 5A as a power supply. Therefore, the USB Type-C interface circuit has a narrow space between the terminals, and requires precise connection. However, the USB Type-C interface circuit is also an external interface that supports hot plugging, so it is inserted and removed frequently, and is prone to poor contact due to wear caused by gouging and insertion and removal.

The second problem is that the user cannot determine the cause of an abnormality (e.g., whether it is the device or the cable) that is causing the device not to work properly or not to be recognized until they actually disconnect it, replace the device or cable, or perform other isolation procedures.

The reason is as follows. Abnormal conditions of high-speed signal lines can be notified by the controller of each device using the communication protocol of each high-speed signal. However, the device controller can only notify abnormal conditions that it can detect. As an example, assume that a high-speed signal switch (Multiplexer: MUX), which is indispensable for using a USB Type-C interface circuit, is broken. In this case, well-known USB Type-C interface circuits do not have a mechanism to notify the device controller of the abnormality. This is because many device controllers have been in use since before the USB Type-C standard was established, and were not designed for use with USB Type-C interface circuits. In addition, since switching high-speed signals using a MUX is a function that became necessary for using a USB Type-C interface circuit, there is no mechanism for notifying the state between the device controller and the MUX.

On the other hand, Patent Documents 1 to 6 each have the following problems.

Patent Document 1 and Patent Document 2 simply determine whether the connected device is a Type-C device or a non-Type-C device, and do not notify the host device of an abnormal state of the device.

Patent Document 3 only detects abnormal states of the power line (VBUS) within the Type-C controller, and does not notify the host device of the abnormal state of the device.

Patent Document 4 merely detects a short circuit between terminals caused by the intrusion of foreign matter into a Type-C connector, but does not notify a host device of an abnormal state of the device.

Patent document 5 merely discloses electronic devices that can prevent burnout accidents, but does not notify a host device of an abnormal state of the device.

Patent Document 6 discloses a technique for notifying a short circuit when a short circuit is detected, using communication on a CC line. In other words, Patent Document 6 only detects short circuits on bus lines as an abnormal state of a device, and does not detect abnormal states that occur within the device for other reasons. In other words, Patent Document 6 assumes in advance that the cause of the abnormality is a short circuit, and is unable to detect other causes.

The object of the present invention is to provide a method for notifying a status in a USB Type-C interface circuit that solves the above-mentioned problems.

As a first aspect of the present invention, a status notification method in a USB Type-C interface circuit is a status notification method in a USB Type-C interface circuit in which a device and a higher-level device are connected via a Type-C cable conforming to the USB (Universal Serial Bus) Type-C standard, the Type-C cable includes a CC (Configuration Channel) line, the device has a connector connected to the Type-C cable, a Type-C controller connected to the CC line via the connector, and a device controller that controls the device, and the status notification method includes the device controller detecting an abnormal state that has occurred in the device, the device controller notifying the Type-C controller of detection information representing the detected abnormal state, the Type-C controller analyzing the cause of the abnormal state based on the detection information and obtaining an analysis result, and the Type-C controller notifying the higher-level device of the detection information and the analysis result using the CC line.

As a second aspect of the present invention, a status detection method in a USB Type-C interface circuit is a status notification method in a USB Type-C interface circuit in which a device and a higher-level device are connected via a Type-C cable conforming to the USB (Universal Serial Bus) Type-C standard, the Type-C cable includes a CC (Configuration Channel) line, the device has a connector connected to the Type-C cable, a Type-C controller connected to the CC line via the connector, and a device controller that controls the device, and the status notification method includes the device controller detecting an abnormal state that has occurred in the device, analyzing the cause of the abnormal state based on detection information indicating the detected abnormal state and obtaining an analysis result, the device controller notifying the Type-C controller of the detection information and the analysis result, and the Type-C controller notifying the higher-level device of the detection information and the analysis result using the CC line.

As a third aspect of the present invention, a status notification method in a USB Type-C interface circuit is a status detection method in a USB Type-C interface circuit in which a device and a higher-level device are connected via a Type-C cable conforming to the USB (Universal Serial Bus) Type-C standard, the Type-C cable includes a CC (Configuration Channel) line, the device has a connector connected to the Type-C cable, a Type-C controller connected to the CC line via the connector, a device controller that controls the device, and a dedicated controller that analyzes an abnormal state, and the status notification method includes the device controller detecting an abnormal state that has occurred in the device and notifying the dedicated controller of the detection information, the dedicated controller analyzing the cause of the abnormal state based on the detection information, and notifying the Type-C controller of the analysis result and the detection information, and the Type-C controller notifying the higher-level device of the detection information and the analysis result using the CC line.

As a fourth aspect of the present invention, a status notification method in a USB Type-C interface circuit is a status notification method in a USB Type-C interface circuit in which a device and a higher-level device are connected via a Type-C cable that complies with the USB (Universal Serial Bus) Type-C standard, the Type-C cable includes a CC (Configuration Channel) line and a Type-C controller connected to the CC line, and in the status notification method, the Type-C controller detects that an abnormality has occurred in the Type-C cable and obtains detection information, the Type-C controller analyzes the detection information and obtains an analysis result, and the Type-C controller notifies the higher-level device of the detection information and the analysis result using the CC line.

The present invention can improve reliability and maintainability.

1 is a diagram showing a connection configuration of a system using a USB Type-C interface circuit according to a first embodiment of the present invention. 4 is a flowchart for explaining an example of a state notification method in the USB Type-C interface circuit according to the first embodiment of the present invention. 10 is a flowchart for explaining a modified example of a state notification method in the USB Type-C interface circuit according to the first embodiment of the present invention. FIG. 11 is a diagram showing a connection configuration of a system using a USB Type-C interface circuit according to a second embodiment of the present invention. 10 is a flowchart illustrating an example of a state notification method in a USB Type-C interface circuit according to a second embodiment of the present invention. 13 is a flowchart illustrating an example of a state notification method in a USB Type-C interface circuit according to a third embodiment of the present invention. FIG. 2 is a diagram for explaining an operation (first embodiment) when an abnormality occurs in a device MUX in communication using the USB Type-C interface circuit according to the first embodiment shown in FIG. FIG. 5 is a diagram for explaining an operation (second embodiment) when an abnormality occurs in a device MUX in communication using the USB Type-C interface circuit according to the second embodiment shown in FIG. FIG. 5 is a diagram showing a configuration in which two different input signals, a USB signal and a Displayport signal, are supplied to a device MUX from a main controller in communication using a USB Type-C interface circuit according to the second embodiment shown in FIG. FIG. 11 is a block diagram showing a device having a mechanism according to a second embodiment.

First, we will provide an overview of the present invention.

The present invention aims to solve the problems for devices using a USB Type-C interface circuit by the following steps (1) to (4).
(1) The device controller detects an abnormal condition that occurs within the device.
(2) The device controller notifies the Type-C controller of the detected information.
(3) The Type-C controller analyzes the cause of the abnormality.
(4) The abnormal condition and analysis results are notified to the upper Type-C controller via the Configuration Channel (CC) line.

In this case, the role of (3) may be performed by the device controller. In that case, the device controller may notify the Type-C controller of the abnormal condition and the analysis result, and the Type-C controller may simply notify the upper Type-C controller using the CC line.

Next, we will explain the effects of the present invention.

The first effect is that this can be achieved by notifying abnormal conditions and analysis results using the CC line of the USB Type-C interface circuit, without the need to add a new interface.

The reason is as follows: The CC line is a signal line that is always present when using a USB Type-C interface circuit. During normal operation, the CC line notifies the USB Type-C interface circuit of the cable orientation, required power supply (VBUS) voltage, and high-speed signal information to be used as part of negotiation functions during device recognition.

Once negotiation is complete when connecting a device, the upper Type-C controller simply monitors the voltage level and determines whether the cable has been inserted or removed; no communication is carried out using this signal line (CC line).

Normally, connected devices will remain connected unless the user frequently plugs and unplugs them, which means that the CC line is used infrequently.

In addition, device controllers generally support communication protocols for abnormal situations, but these communications are also carried out over signal lines that are operating normally (during the time it takes to notify of an abnormal state). As a result, this communication affects the performance of normal operations.

Therefore, in this invention, by notifying abnormal status during times when the CC line is used less frequently, it is possible to notify abnormalities without affecting operational performance.

The second effect is that while the abnormal conditions that can be supported by normal high-speed signal abnormality notifications are limited to those that comply with each communication protocol, the present invention allows the device controller to detect and notify abnormal conditions that are not supported by each communication protocol.

The reason for this is as follows: The CC line is currently separate from each high-speed signal and device controller, and is a signal line used solely for communication between the upper level device and the Type-C controller of the device. Therefore, the CC line can be thought of as a means of notifying, using a unique protocol, of abnormal conditions that are not supported by each high-speed signal or device controller.

The fact that the CC line can be thought of as a means of sending notifications using a unique protocol means that the Configuration Channel (CC) communication protocol (BMC, etc.) used in the USB Type-C standard is completely different from the communication protocols used for high-speed signals such as USB 2.0, USB 3.0, and Displayport. In addition, the signal lines used for this communication are also separate.

The CC line is a signal line originally defined in the USB Type-C standard and is a known technology.

However, in this invention, the error status of each device is communicated to a higher-level device using a CC line, and there is no existing technology that can communicate the error status of a device using a CC line.

Although it is said to be a proprietary protocol here, the communications protocol used when negotiating as a USB Type-C interface circuit is defined in the standard (USB Power Delivery).

In the present invention, communication may be performed according to that protocol, or a new protocol for abnormal communication may be prepared. In that case, the USB Type-C controller will encode/decode the communication, so it will be necessary to customize the firmware (F/W) of the Type-C controller.

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[Embodiment 1]
FIG. 1 is a diagram showing a connection configuration of a system using a USB Type-C interface circuit 100 according to a first embodiment of the present invention.

[Configuration Description]
The USB Type-C interface circuit 100 includes a host device 200, which is a higher-level device, a USB Type-C device 300, and a Type-C cable 400 that connects the host device 200 and the USB Type-C device 300. The USB Type-C device 300 is also simply called a device. The Type-C cable 400 is also called a USB cable.

The upper device (host device) 200 includes an upper connector 210, a main controller 220, an upper Type-C controller 230, an upper MUX 240, a power supply (VBUS) control circuit 250, and a power supply (VCONN) control circuit 260 for the Type-C cable. A power supply 500 is connected to the upper device (host device) 200.

The upper connector 210 is connected to the Type-C cable 400. The main controller 220 acts as a system control unit such as a CPU (central processing unit) or chipset. The upper Type-C controller 230 performs signal processing related to the USB Type-C interface circuit 100. The upper MUX 240 is a switch that switches high-speed signals.

The device 300 includes a device connector 310, a device controller 320, and a device Type-C controller 330. The illustrated device 300 includes a device MUX 340.

The device connector 310 is connected to the Type-C cable 400. The device controller 320 controls the entire device 300. The device Type-C controller 330 performs signal processing related to the USB Type-C interface circuit 100. The device MUX 340 is a switch that switches high-speed signals.

The device 300 may also have a power supply control circuit (not shown) for supplying power (VBUS) from the device 300 to the higher-level device 200.

The Type-C cable 400 includes a CC (Configuration Channel) line 410. The illustrated Type-C cable 400 includes a cable Type-C controller 420.

The upper Type-C controller 230 performs VBUS control, VCONN control, connection control with the Type-C device 300 (including the Type-C cable 400), detection of the front/back connection state of the cable, and outputs control signals for switching high-speed signals based on information about the connected device.

The main controller 220 may be connected internally or externally to the upper Type-C controller 230, or may be independent of the upper Type-C controller 230.

[Operation Description]
Next, the operation of the USB Type-C interface circuit 100 will be described.

In the first embodiment of the present invention, the function is configured such that the device Type-C controller 330 is connected so as to be able to communicate with the higher-level device 200. An example of a signal in this case is serial communication such as I2C (Inter-Integrated Circuit).

The host Type-C controller 230 and the device Type-C controller 330 are connected by a CC line 410. The CC line 410 performs packet communication using the BFSK (Binary Frequency Shift Keying) method (USB Power Delivery Rev1) or the BMC (Biphase Mark Coding) method (USB Power Delivery Rev2 or later). In this packet communication, information such as the specifications of the power supply that can be supplied on the upper device 200 side, the required power supply on the device 300 side, and the high-speed signal to be used is exchanged between the Type-C controllers 230 and 330. The timing of this communication is after the Type-C cable 400 is connected to the upper device 200 and the device 300 and the front and back connection status of the cable is detected.

In the first embodiment, after the above communication is completed, the CC line 410 is not used for packet communication, but is used to monitor the connection status of the Type-C cable 400.

This monitoring of the connection status is different from polling using SOF (Soft of Frame) packets as in USB communication, and is performed by the upper Type-C controller 230 monitoring the current or voltage value of the CC line 410. When the CC line 410 detects that the Type-C cable 400 has been unplugged, the upper Type-C controller 230 operates the discharge circuit in the VBUS control circuit 250 to quickly drop VBUS.

In the first embodiment of the present invention, as a means of communicating an abnormal state of the device 300, a time when the CC line 410 is infrequently used and no packet communication is performed while the connection status of the CC line 410 is being monitored is allocated to packet communication in the abnormal state.

With reference to FIG. 2, an example of a state notification method in the USB Type-C interface circuit 100 according to the first embodiment of the present invention will be described.

First, the device controller 320 detects an abnormal condition that has occurred within the device 300 (step S101).

Next, the device controller 320 notifies the device Type-C controller 330 of detection information indicating the detected abnormal condition (step S102).

Next, the device Type-C controller 330 analyzes the cause of the abnormal state based on the detection information and obtains the analysis result (step S103).

Finally, the device Type-C controller 330 notifies the upper Type-C controller 230 of the upper device 200 of the detection information and the analysis result using the CC line 410 (step S104). At this time, as described above, the device Type-C controller 330 notifies the upper Type-C controller 230 of the upper device 200 of the detection information and the analysis result using the CC line 410 during a time when the CC line 410 is used infrequently.

With reference to FIG. 3, a modified example of the state notification method in the USB Type-C interface circuit 100 according to the first embodiment of the present invention will be described.

First, the device controller 320 detects an abnormal condition that has occurred within the device 300 (step S0101).

Next, the device controller 320 analyzes the cause of the abnormal condition based on the detection information indicating the detected abnormal condition and obtains an analysis result (step S102A).

Next, the device controller 320 notifies the device Type-C controller 330 of the detection information and analysis results (step S103A).

Finally, the device Type-C controller 330 notifies the upper Type-C controller 230 of the upper device 200 of the detection information and the analysis result using the CC line 410 (step S104). At this time, as described above, the device Type-C controller 330 notifies the upper Type-C controller 230 of the upper device 200 of the detection information and the analysis result using the CC line 410 during a time when the CC line 410 is used infrequently.

Next, the effects of the first embodiment will be described.

The first effect is that reliability can be improved. This is because the detection information and analysis information can be notified to the higher-level device 200, making it possible to identify abnormalities in the USB Type-C interface circuit 100.

The second effect is that maintainability can be improved. This is because the location of the abnormality can be identified, and recovery methods and replacement items become clear without the user having to perform any analysis.

[Embodiment 2]
FIG. 4 is a diagram showing a connection configuration of a system using a USB Type-C interface circuit 100A according to the second embodiment of the present invention.

[Configuration Description]
The illustrated USB Type-C interface circuit 100A has a configuration and operates similarly to the USB Type-C interface circuit 100 illustrated in Fig. 1, except that the configuration of the device has been changed as described below. Therefore, the device is given the reference symbol 300A. The same reference symbols are given to components similar to those of the USB Type-C interface circuit 100 in Fig. 1, and their description will be omitted for the sake of simplicity.

Device 300A has a configuration and operates similarly to device 300 shown in FIG. 1, except that device 300A further includes a dedicated controller 350 for analyzing abnormal conditions.

[Operation Description]
The basic operation of the USB Type-C interface circuit 100A is similar to that of the USB Type-C interface circuit 100 described above.

With reference to FIG. 5, an example of a state notification method in the USB Type-C interface circuit 100A according to the second embodiment of the present invention will be described.

First, the device controller 320 detects an abnormal condition that has occurred within the device 300A (step S101).

Next, the device controller 320 notifies the dedicated controller 350 of the detection information (step S102B).

Next, the dedicated controller 350 analyzes the cause of the abnormal state based on the detection information, and notifies the device Type-C controller 330 of the analysis result and the detection information (step S103B).

Finally, the device Type-C controller 330 notifies the upper Type-C controller 230 of the upper device 200 of the detection information and the analysis result using the CC line 410 (step S104). At this time, as described above, the device Type-C controller 330 notifies the upper Type-C controller 230 of the upper device 200 of the detection information and the analysis result using the CC line 410 during a time when the CC line 410 is used infrequently.

The effects of the second embodiment are similar to those of the first embodiment described above.

[Embodiment 3]
A USB Type-C interface circuit 100 according to the third embodiment of the present invention has a system connection configuration similar to that shown in FIG.

As shown in FIG. 1, a cable Type-C controller 420 is built into the Type-C cable 400. This cable Type-C controller 420 is connected to the upper Type-C controller 230 via a CC line 410, similar to the device Type-C controller 330.

[Operation Description]
An example of a state notification method in the USB Type-C interface circuit 100 according to the third embodiment of the present invention will be described with reference to FIG.

First, the cable Type-C controller 420 detects that an abnormality has occurred in the Type-C cable 400 and obtains detection information (step S201).

Then, the cable Type-C controller 420 analyzes the detection information and obtains an analysis result (step S202).

Finally, the cable Type-C controller 420 notifies the upper Type-C controller 230 of the upper device 200 of the detection information and the analysis result using the CC line 410 (step S203). At this time, as described above, the cable Type-C controller 420 notifies the upper Type-C controller 230 of the upper device 200 of the detection information and the analysis result using the CC line 410 during a time when the CC line 410 is used infrequently.

This allows the user to be notified that the Type-C cable 400 is in an abnormal state.

Next, we will explain the third embodiment in more detail.

The high-speed signal input to the device MUX 340 is only shared with the device 300 through the Type-C cable 400. Therefore, possible failures in the Type-C cable 400 include a break or a short circuit.

The USB Type-C standard also defines a cable called e-Marker, which has a cable Type-C controller 420 inside the Type-C cable 400. The cable Type-C controller 420 operates by receiving a dedicated power supply (VCONN) from the host device 200.

The function of the cable Type-C controller 420 defined in the existing USB Type-C standard is to monitor whether the specifications of the power supply (VBUS) to be supplied from the host device 200 to the device 300 through the Type-C cable 400 meet the power supply specifications that can be passed through the Type-C cable 400. In other words, the function of the existing cable Type-C controller 420 is to protect the Type-C cable 400 from problems such as burnout caused by passing a current exceeding the cable's specifications.

The above monitoring results are communicated with the upper Type-C controller 230 via the Configuration Channel (CC line) 410. The current USB Type-C standard does not have the functionality to enable the cable Type-C controller 420 to monitor the state of high-speed signals other than power.

For this reason, in the third embodiment, the cable Type-C controller 420 is provided with a mechanism for monitoring high-speed signals between the device MUX 340 and the device controller 320 on the device 300 side. This makes it possible to detect abnormalities in the state of the Type-C cable 400.

This mechanism can be realized, for example, by implementing a dedicated controller that integrates the functions of a measuring instrument called an analyzer, which can decode high-speed signal waveforms, into a single chip in the cable Type-C controller 420.

Next, as a first embodiment of the present invention, with reference to FIG. 7, an operation when an abnormality occurs in the device MUX 340 during communication using the USB Type-C interface circuit 100 according to the first embodiment shown in FIG. 1 will be described.

First, we will explain the process A1 in Figure 7.

If an abnormality occurs in device MUX 340, the signal passing through device MUX 340 is not input to device 300 normally, and device 300 does not respond.

In such a situation, in the related technology, the host device 200 can detect from the signal conditions that the device 300 is not recognized, and notify the application (AP) 600. However, all that can be notified is the fact that the device is not recognized, and it is not possible to know detailed information about which part is causing the abnormality.

In response to this, the device controller 320 itself can know that no signal is being received even though the power supply (VBUS) is on. Therefore, in this first embodiment, the device controller 320 can notify the device Type-C controller 330 of the fact that no signal is being received as detection information.

At this time, as in step S102A of FIG. 3, the device controller 320 may analyze the possible abnormal state and notify the device Type-C controller 330 of the analysis result. Alternatively, as in step S103 of FIG. 2, the analysis may be performed within the device Type-C controller 330 that has received the notification of the abnormal state.

The communication between the device controller 320 and the device Type-C controller 330 may be serial communication such as I2C (Inter-Integrated Circuit) or parallel communication using a bit pattern determined in advance for each error content.

Next, we will explain the process of A2 in Figure 7.

After the above process A1, as in step S104 of FIG. 2 or FIG. 3, the device Type-C controller 330 performs serial communication with the upper Type-C controller 230 using the CC line 410.

The serial communication at this time uses the BMC (Biphase Mark Coding) method or BFSK (Binary Frequency Shift Keying) method defined in USB Type-C Power Delivery, and is performed using a packet configuration for abnormal status communication newly defined in this invention.

Finally, we will explain the process of A3 in Figure 7.

The upper Type-C controller 230, which has received the abnormal status communication as a result of the processing in A2 above, notifies the main controller 220 and application 600 of the information, and notifies the user.

This allows the user to know that the cause of the abnormality in device 300 is that a signal is not reaching device controller 320 and that device MUX 340 is abnormal.

Next, as a second embodiment of the present invention, with reference to FIG. 8, an operation when an abnormality occurs in the device MUX 340 during communication using the USB Type-C interface circuit 100A according to the second embodiment shown in FIG. 4 will be described.

First, we will explain the process B1 in Figure 8.

The device controller 320 notifies the dedicated controller 350 of the detection information that a signal has not reached the device controller 320.

Next, we will explain the process of B2 in Figure 8.

At this time, as in step S103B of FIG. 5, the dedicated controller 350 analyzes possible abnormal conditions and notifies the device Type-C controller 330 of the analysis results.

Next, we will explain the process of B3 in Figure 8.

After the previous process of B2, as in step S104 of FIG. 5, the device Type-C controller 330 performs serial communication with the upper Type-C controller 230 using the CC line 410.

Finally, we will explain the process of B4 in Figure 8.

The upper Type-C controller 230, which has received the abnormal status communication as a result of the processing in B3 above, notifies the main controller 220 and application 600 of the information, and notifies the user.

This allows the user to know that the cause of the abnormality in device 300 is that a signal is not reaching device controller 320 and that device MUX 340 is abnormal.

Next, we will explain the second embodiment of the present invention in more detail.

A multiplexer (MUX) acts as a switch to switch between multiple signals, and is generally implemented as a single-chip IC (integrated circuit).

This IC is an electrical switch that can switch the destination of multiple output ports for multiple inputs. In addition, as a control signal for this switching, it is possible to input a number of switching signals according to the combination of inputs and outputs. However, since device MUX 340 is a passive device, it does not have a mechanism for the IC itself to notify a higher-level device of an abnormality. An abnormality here could be, for example, a failure in the parts that make up the switch inside the IC that prevents the signal from switching.

Therefore, in this second embodiment, a mechanism is provided that can notify a higher-level device of an abnormality, as described below.

The signal that passes through device MUX 340 is then input to the device controller (described later). The device controller itself can determine whether a signal different from the signals it supports has been input using the device's internal firmware, etc. At this time, the device controller notifies of abnormal status in accordance with the communication protocol of each high-speed signal.

Figure 9 shows a configuration in which two different input signals, a USB signal and a Displayport signal, are supplied to the device MUX 340 from a main controller 220 such as a CPU or chipset.

As shown in FIG. 9, device MUX 340 includes a device controller 322 for Displayport signals and a device controller 324 for USB signals.

In such a configuration, in the related art, the following states are considered to be states that are recognized as abnormal by the user.
1) The monitor connected to the Displayport is not displaying anything.
2) USB 3.0 devices (such as USB memory sticks) are not recognized at USB 3.0 Super Speed.

Of these, 1) relates to the state of the monitor itself beyond the device controller 322. In this case, even if two pairs of the maximum four pairs of video signals are not received, the monitor can still display the image, although the specifications will be reduced.

As for 2), if device 300A supports the backward-compatible USB 2.0 High Speed, it will function as a USB memory.

Therefore, in the second embodiment of the present invention, a mechanism is provided for inferring a failure in device MUX 340 from an abnormal state of connected device 300A, as described in detail below.

For example, when device 300A is operating at lower specifications in both 1) and 2) above, device controllers 322 and 324 can notice an abnormal state of device 300A. This mechanism is an existing technology, and device controllers 322 and 324 can notify upper device 200 of the abnormal state.

However, in this notification, it is not possible to infer and send the specific location of the failure (device MUX 340 in this example). The reasons are as follows. First, because this technology exists before the construction of the USB Type-C interface circuit mechanism, the firmware of device controllers 322, 324 is not adapted to infer and notify of a failure in device MUX 340. Second, because the location of the failure is the signal line connected to the higher-level device 200, there is no way to send a notification to the higher-level device 200. In other words, with the current mechanism, the higher-level device 200 can only recognize the fact that "it is not operating at USB 3.0 Super Speed."

Figure 10 is a block diagram showing a device 300A having a mechanism according to the second embodiment.

A path for notifying an abnormal state is provided between the dedicated controller 350 and the device controllers 320, 322, and 324. A path for notifying an analysis result is provided between the dedicated controller 350 and the device Type-C controller 330.

For example, assume that a failure occurs in the USB 3.0 Super Speed of device MUX 340, as shown in Figure 10.

In this case, the device controller 322 notifies the dedicated controller 350 of a normal state, indicating that the Displayport is operating normally and that no abnormalities are found within the device controller 322. On the other hand, the device controller 324 notifies the dedicated controller 350 of an abnormal state, indicating that the device controller 324 is not operating at USB 3.0 Super Speed but that no abnormalities are found within the device controller 324.

The dedicated controller 350 analyzes these normal and abnormal states and obtains an analysis result indicating that a failure of the device MUX 340 is suspected. The dedicated controller 350 notifies the device Type-C controller 330 of the abnormal state and the analysis result.

The device Type-C controller 330 notifies the higher-level device 200 of the notified abnormal state and analysis results by using the Configuration Channel (CC line) 410.

In this way, in the second embodiment, a path is provided to analyze and notify the abnormal state of each device controller 320, 322, 324 externally, and the device Type-C controller 330 can notify the upper device 200 of the abnormal state and the analysis results by using the Configuration Channel (CC line) 410.

This mechanism also has the following advantages. In related technologies, a dedicated signal line for each high-speed signal is used to notify of an abnormal state. In the case of a USB Type-C interface circuit, an abnormal state can be notified by another signal line. Suppose that a part of device 300A is in an abnormal state, while the other parts are operating normally. In this case, instead of incorporating operations related to communication in an abnormal state into normal operations within the target device controller, by having dedicated controller 350 process them as in this second embodiment, each device controller can focus only on the operation of the normal parts.

The present invention has been described above with reference to embodiments and examples, but the present invention is not limited to the above embodiments and examples. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

As an example of how this invention can be used, it can be used in terminals that use USB Type-C interface circuits.

100, 100A USB Type-C interface circuit 200 Host device (upper device)
210 Upper connector 220 Main controller 230 Upper Type-C controller 240 Upper MUX
250 VBUS control circuit 260 VCONN control circuit 300, 300A USB Type-C device (device)
310 Device connector 320, 322, 324 Device controller 330 Device Type-C controller 340 Device MUX
350 Dedicated controller 400 Type-C cable (USB cable)
410 CC (Configuration Channel) line 420 Cable Type-C controller 500 Power supply 600 Application (AP)

Claims (6)

A state notification method in a USB (Universal Serial Bus) Type-C interface circuit in which a device and a higher-level device are connected via a Type-C cable conforming to the USB Type-C standard, comprising:
The Type-C cable includes a Configuration Channel (CC) line,
the device includes a connector connected to the Type-C cable, a Type-C controller connected to the CC line via the connector, and a device controller that controls the device;
The status notification method includes:
The device controller detects an abnormal condition that occurs within the device;
The device controller notifies the Type-C controller of detection information indicating the detected abnormal state;
the Type-C controller analyzes a cause of the abnormal state detected by the device controller based on the detection information and obtains an analysis result;
The Type-C controller notifies the upper device of the detection information and the analysis result by using the CC line;
The device includes a switch for high speed signals;
When an abnormality occurs in the switch, the device controller detects that a signal has not reached the device controller due to the occurrence of the abnormality in the switch as the abnormal state, and notifies the Type-C controller of the fact that the signal has not reached as the detection information;
The Type-C controller analyzes the detection information indicating that the notified signal has not arrived , and notifies the upper device of the result of the determination that an abnormality has occurred in the switch as the analysis result.
A status notification method for a USB Type-C interface circuit. the Type-C controller notifies the host device of the detection information and the analysis result by using the CC line during a time when the CC line is used infrequently;
The state notification method in the USB Type-C interface circuit according to claim 1. A state notification method in a USB (Universal Serial Bus) Type-C interface circuit in which a device and a higher-level device are connected via a Type-C cable conforming to the USB Type-C standard, comprising:
The Type-C cable includes a Configuration Channel (CC) line,
the device includes a connector connected to the Type-C cable, a Type-C controller connected to the CC line via the connector, and a device controller that controls the device;
The status notification method includes:
the device controller detects an abnormal state occurring within the device, and based on detection information indicating the detected abnormal state, analyzes the cause of the abnormal state and obtains an analysis result;
The device controller notifies the Type-C controller of the detection information and the analysis result;
The Type-C controller notifies the upper device of the detection information and the analysis result by using the CC line;
The device includes a switch for high speed signals;
When an abnormality occurs in the switch, the device controller detects, as the abnormal state, that a signal has not reached the device controller due to the occurrence of the abnormality in the switch, and obtains, as the analysis result, a result that it has been determined that an abnormality has occurred in the switch based on the fact that the signal has not reached the device controller as the detection information.
A status notification method for a USB Type-C interface circuit. The Type-C controller notifies the host device of the detection information and the analysis result by using the CC line during a time when the CC line is used infrequently.
The state notification method in the USB Type-C interface circuit according to claim 3. A device using a USB (Universal Serial Bus) Type-C interface circuit that connects to an information processing device via a Type-C cable that complies with the USB Type-C standard,
The Type-C cable includes a Configuration Channel (CC) line,
the device includes a connector connected to the Type-C cable, a Type-C controller connected to the CC line via the connector, and a device controller that controls the device;
The device controller detects an abnormal state that has occurred in the device, and notifies the Type-C controller of detection information indicating the detected abnormal state;
The Type-C controller analyzes the cause of the abnormal state detected by the device controller based on the detection information to obtain an analysis result, and notifies the information processing device of the detection information and the analysis result via the CC line.
The device includes a switch for high speed signals;
When an abnormality occurs in the switch, the device controller detects that a signal has not reached the device controller due to the occurrence of the abnormality in the switch as the abnormal state, and notifies the Type-C controller of the fact that the signal has not reached as the detection information;
The Type-C controller analyzes the detection information indicating that the notified signal has not arrived , and notifies the information processing device of the result of determining that an abnormality has occurred in the switch as the analysis result.
A device that uses a USB Type-C interface circuit. In an information processing system having a USB (Universal Serial Bus) Type-C interface circuit in which a device and a higher-level device are connected via a Type-C cable conforming to the USB Type-C standard,
The Type-C cable includes a Configuration Channel (CC) line,
the device includes a connector connected to the Type-C cable, a Type-C controller connected to the CC line via the connector, and a device controller that controls the device;
The device controller detects an abnormal state that has occurred in the device, and notifies the Type-C controller of detection information indicating the detected abnormal state;
The Type-C controller analyzes a cause of the abnormal state detected by the device controller based on the detection information to obtain an analysis result, and notifies the host device of the detection information and the analysis result via the CC line;
The device includes a switch for high speed signals;
When an abnormality occurs in the switch, the device controller detects that a signal has not reached the device controller due to the occurrence of the abnormality in the switch as the abnormal state, and notifies the Type-C controller of the fact that the signal has not reached as the detection information;
The Type-C controller analyzes the detection information indicating that the notified signal has not arrived , and notifies the upper device of the result of the determination that an abnormality has occurred in the switch as the analysis result.
An information processing system having a USB Type-C interface circuit.

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